A hand is silhouetted in front of a computer screen in this picture illustration taken in Berlin May 21, 2013. REUTERS/Pawel Kopczynski

“We see aggressive and increased cyber spying and cyber operations that could potentially endanger German government officials, members of parliament and employees of democratic parties,” Hans-Georg Maassen, head of the BfV spy agency, said in statement.

Maassen, who raised similar concerns about Russian efforts to interfere in German elections last month, cited what he called increasing evidence about such efforts and said further cyber attacks were expected.

The agency said it had seen a wide variety of Russian propaganda tools and “enormous use of financial resources” to carry out “disinformation” campaigns aimed at the Russian-speaking community in Germany, political movements, parties and other decision makers.

The goal was to spread uncertainty, strengthen extremist groups and parties, complicate the work of the federal government and “weaken or destabilize the Federal Republic of Germany”.

The agency said it had seen a “striking increase” in spear-phishing attacks attributed to Russian hacking group APT 28, also known as “Fancy Bear” or Strontrium. It is the same group blamed for the hack of the U.S. Democratic National Committee this year and a cyber attack on the German parliament in 2015.

The attacks were directed against German parties and lawmakers and were carried out by government bodies posing as “hacktivists”, the agency said.

German officials have accused Moscow of trying to manipulate German media to fan popular angst over issues like the migrant crisis, weaken voter trust and breed dissent within the European Union so that it drops sanctions against Moscow.

But intelligence officials have stepped up their warnings in recent weeks, alarmed about the number of attacks.

Last month, German Chancellor Angela Merkel said she could not rule out Russia interfering in Germany’s 2017 election through Internet attacks and misinformation campaigns.

Estonian Foreign Minister Sven Mikser on Thursday said he expected Russia to continue a campaign of “psychological warfare” and spreading false information after the cyber attacks launched during the U.S. election.

“It’s a pretty safe bet that they will try to do it again,” he told Reuters in Hamburg at a meeting of the Organization for Security and Cooperation in Europe. “They will try to surprise us. That’s something that we should be very careful to look at and try to protect ourselves from.”

Estonia has acted to shore up its cyber security after attacks that shut down private and government websites in 2007, which Estonia blamed on Russia. The Kremlin denied involvement.

Russian officials have denied all accusations of manipulation and interference intended to weaken the European Union or to affect the U.S. presidential election.

U.S. intelligence officials had warned in the run-up to the Nov. 8 presidential election of efforts to undermine the credibility of the vote that they believed were backed by the Russian government.